The Allis-Chalmers (Type R) Small Gyratory Reduction Crusher is designed for large capacity, fine crushing and incorporates many improvements over other gyratory type crushers previously manufactured by this company. The most distinctive feature of the Type R Crusher is the built-in, oil filled hydraulic jack used for fast, positive change of crusher setting while crusher … Read more
This test method specifies the apparatus, instrumentation, and procedures for determining unconfined compressive strength of intact rock core specimens. This procedure is identical to ASTM D 2938 except that the cores are tested after cutting without grinding, and neoprene caps are used on the specimen ends. Unconfined Compressive Strength Test Procedure Check the ability of the spherical seat … Read more
HPGR or high-pressure grinding rolls have made broad advances into nonferrous metal mining. The technology is now widely viewed as a primary milling alternative, and there arc a number of large installations commissioned in recent years. After these developments, an HPGR based circuit configuration would often be the base case for certain ore types, such as … Read more
Toward the foregoing goal, engineers investigated the energy efficiency of crushing for less than ideal cases. In the first experiment they studied the effect of factors such as using a deep bed of particles, a situation usually present in a ball mill. The same type of slow crushing experiment described above was performed, but with a … Read more
Ore Sorting helps the economics of mining when ore becomes diluted by country rock because of narrow slopes or because of weak wall rock, or when it naturally contains barren material which is distinguishable from the ore, sorting and rejecting the worthless rock may be economical. This is done in a casual manner at some … Read more
Methods used in Crushing & Screening Plants on ore range from a simple combination of a grizzly and one crusher to an elaborate arrangement in series of grizzly, jaw crusher, screens, and rolls or cone crushers. Crushing is done underground at a few large mines. In general, the jaw crusher is the most suitable primary machine, yet … Read more
Let’s review the steps to collect a sample of coarse rocks such as primary Crusher product. The procedure requires that Process Equipment be shut down and so it is important to organize the work to minimize lost time. First the particular conveyor where the sample is to be collected is identified, next, one to two … Read more
UNTIL THE THIRD THEORY OF COMMINUTION of “Work Index” method of determining crushing and grinding mill size was introduced, there was no way of accurately figuring the most applicable, most economical size of crushing and grinding mill. Naturally, with little or no factual operating data correlated in useful form, it was easy enough, even for … Read more
A-Z Guide to Screening Ore, Rock & Aggregate A simple definition of a “screen” is a machine with surface(s) used to classify materials by size. Screening is defined as “The mechanical process which accomplishes a division of particles on the basis of size and their acceptance or rejection by a screening surface”. Knowledge of screening comes … Read more